export default {
	props: {
		localdata: {
			type: [Array, Object],
			default () {
				return []
			}
		},
		spaceInfo: {
			type: Object,
			default () {
				return {}
			}
		},
		collection: {
			type: String,
			default: ''
		},
		action: {
			type: String,
			default: ''
		},
		field: {
			type: String,
			default: ''
		},
		orderby: {
			type: String,
			default: ''
		},
		where: {
			type: [String, Object],
			default: ''
		},
		pageData: {
			type: String,
			default: 'add'
		},
		pageCurrent: {
			type: Number,
			default: 1
		},
		pageSize: {
			type: Number,
			default: 500
		},
		getcount: {
			type: [Boolean, String],
			default: false
		},
		getone: {
			type: [Boolean, String],
			default: false
		},
		gettree: {
			type: [Boolean, String],
			default: false
		},
		manual: {
			type: Boolean,
			default: false
		},
		value: {
			type: [Array, String, Number],
			default () {
				return []
			}
		},
		modelValue: {
			type: [Array, String, Number],
			default () {
				return []
			}
		},
		preload: {
			type: Boolean,
			default: false
		},
		stepSearh: {
			type: Boolean,
			default: true
		},
		selfField: {
			type: String,
			default: ''
		},
		parentField: {
			type: String,
			default: ''
		},
		multiple: {
			type: Boolean,
			default: false
		},
		map: {
			type: Object,
			default () {
				return {
					text: "text",
					value: "value"
				}
			}
		}
	},
	data() {
		return {
			loading: false,
			errorMessage: '',
			loadMore: {
				contentdown: '',
				contentrefresh: '',
				contentnomore: ''
			},
			dataList: [],
			selected: [],
			selectedIndex: 0,
			page: {
				current: this.pageCurrent,
				size: this.pageSize,
				count: 0
			}
		}
	},
	computed: {
		isLocalData() {
			return !this.collection.length;
		},
		isCloudData() {
			return this.collection.length > 0;
		},
		isCloudDataList() {
			return (this.isCloudData && (!this.parentField && !this.selfField));
		},
		isCloudDataTree() {
			return (this.isCloudData && this.parentField && this.selfField);
		},
		dataValue() {
			let isModelValue = Array.isArray(this.modelValue) ? (this.modelValue.length > 0) : (this.modelValue !== null ||
				this.modelValue !== undefined);
			return isModelValue ? this.modelValue : this.value;
		},
		hasValue() {
			if (typeof this.dataValue === 'number') {
				return true
			}
			return (this.dataValue != null) && (this.dataValue.length > 0)
		}
	},
	created() {
		this.$watch(() => {
			let al = [];
			['pageCurrent',
				'pageSize',
				'spaceInfo',
				'value',
				'modelValue',
				'localdata',
				'collection',
				'action',
				'field',
				'orderby',
				'where',
				'getont',
				'getcount',
				'gettree'
			].forEach(key => {
				al.push(this[key])
			});
			return al
		}, (newValue, oldValue) => {
			let needReset = false
			for (let i = 2; i < newValue.length; i++) {
				if (newValue[i] != oldValue[i]) {
					needReset = true
					break
				}
			}
			if (newValue[0] != oldValue[0]) {
				this.page.current = this.pageCurrent
			}
			this.page.size = this.pageSize

			this.onPropsChange()
		})
		this._treeData = []
	},
	methods: {
		onPropsChange() {
			this._treeData = [];
		},

		// 填充 pickview 数据
		async loadData() {
			if (this.isLocalData) {
				this.loadLocalData();
			} else if (this.isCloudDataList) {
				this.loadCloudDataList();
			} else if (this.isCloudDataTree) {
				this.loadCloudDataTree();
			}
		},

		// 加载本地数据
		async loadLocalData() {
			this._treeData = [];
			this._extractTree(this.localdata, this._treeData);

			let inputValue = this.dataValue;
			if (inputValue === undefined) {
				return;
			}

			if (Array.isArray(inputValue)) {
				inputValue = inputValue[inputValue.length - 1];
				if (typeof inputValue === 'object' && inputValue[this.map.value]) {
					inputValue = inputValue[this.map.value];
				}
			}

			this.selected = this._findNodePath(inputValue, this.localdata);
		},

		// 加载 Cloud 数据 (单列)
		async loadCloudDataList() {
			if (this.loading) {
				return;
			}
			this.loading = true;

			try {
				let response = await this.getCommand();
				let responseData = response.result.data;

				this._treeData = responseData;

				this._updateBindData();
				this._updateSelected();

				this.onDataChange();
			} catch (e) {
				this.errorMessage = e;
			} finally {
				this.loading = false;
			}
		},

		// 加载 Cloud 数据 (树形)
		async loadCloudDataTree() {
			if (this.loading) {
				return;
			}
			this.loading = true;

			try {
				let commandOptions = {
					field: this._cloudDataPostField(),
					where: this._cloudDataTreeWhere()
				};
				if (this.gettree) {
					commandOptions.startwith = `${this.selfField}=='${this.dataValue}'`;
				}

				let response = await this.getCommand(commandOptions);
				let responseData = response.result.data;

				this._treeData = responseData;
				this._updateBindData();
				this._updateSelected();

				this.onDataChange();
			} catch (e) {
				this.errorMessage = e;
			} finally {
				this.loading = false;
			}
		},

		// 加载 Cloud 数据 (节点)
		async loadCloudDataNode(callback) {
			if (this.loading) {
				return;
			}
			this.loading = true;

			try {
				let commandOptions = {
					field: this._cloudDataPostField(),
					where: this._cloudDataNodeWhere()
				};

				let response = await this.getCommand(commandOptions);
				let responseData = response.result.data;

				callback(responseData);
			} catch (e) {
				this.errorMessage = e;
			} finally {
				this.loading = false;
			}
		},

		// 回显 Cloud 数据
		getCloudDataValue() {
			if (this.isCloudDataList) {
				return this.getCloudDataListValue();
			}

			if (this.isCloudDataTree) {
				return this.getCloudDataTreeValue();
			}
		},

		// 回显 Cloud 数据 (单列)
		getCloudDataListValue() {
			// 根据 field's as value标识匹配 where 条件
			let where = [];
			let whereField = this._getForeignKeyByField();
			if (whereField) {
				where.push(`${whereField} == '${this.dataValue}'`)
			}

			where = where.join(' || ');

			if (this.where) {
				where = `(${this.where}) && (${where})`
			}

			return this.getCommand({
				field: this._cloudDataPostField(),
				where
			}).then((res) => {
				this.selected = res.result.data;
				return res.result.data;
			});
		},

		// 回显 Cloud 数据 (树形)
		getCloudDataTreeValue() {
			return this.getCommand({
				field: this._cloudDataPostField(),
				getTreePath: {
					startWith: `${this.selfField}=='${this.dataValue}'`
				}
			}).then((res) => {
				let treePath = [];
				this._extractTreePath(res.result.data, treePath);
				this.selected = treePath;
				return treePath;
			});
		},

		getCommand(options = {}) {
			/* eslint-disable no-undef */
			let db = uniCloud.database(this.spaceInfo)

			const action = options.action || this.action
			if (action) {
				db = db.action(action)
			}

			const collection = options.collection || this.collection
			db = db.collection(collection)

			const where = options.where || this.where
			if (!(!where || !Object.keys(where).length)) {
				db = db.where(where)
			}

			const field = options.field || this.field
			if (field) {
				db = db.field(field)
			}

			const orderby = options.orderby || this.orderby
			if (orderby) {
				db = db.orderBy(orderby)
			}

			const current = options.pageCurrent !== undefined ? options.pageCurrent : this.page.current
			const size = options.pageSize !== undefined ? options.pageSize : this.page.size
			const getCount = options.getcount !== undefined ? options.getcount : this.getcount
			const getTree = options.gettree !== undefined ? options.gettree : this.gettree

			const getOptions = {
				getCount,
				getTree
			}
			if (options.getTreePath) {
				getOptions.getTreePath = options.getTreePath
			}

			db = db.skip(size * (current - 1)).limit(size).get(getOptions)

			return db
		},

		_cloudDataPostField() {
			let fields = [this.field];
			if (this.parentField) {
				fields.push(`${this.parentField} as parent_value`);
			}
			return fields.join(',');
		},

		_cloudDataTreeWhere() {
			let result = []
			let selected = this.selected
			let parentField = this.parentField
			if (parentField) {
				result.push(`${parentField} == null || ${parentField} == ""`)
			}
			if (selected.length) {
				for (let i = 0; i < selected.length - 1; i++) {
					result.push(`${parentField} == '${selected[i].value}'`)
				}
			}

			let where = []
			if (this.where) {
				where.push(`(${this.where})`)
			}

			if (result.length) {
				where.push(`(${result.join(' || ')})`)
			}

			return where.join(' && ')
		},

		_cloudDataNodeWhere() {
			let where = []
			let selected = this.selected;
			if (selected.length) {
				where.push(`${this.parentField} == '${selected[selected.length - 1].value}'`);
			}

			where = where.join(' || ');

			if (this.where) {
				return `(${this.where}) && (${where})`
			}

			return where
		},

		_getWhereByForeignKey() {
			let result = []
			let whereField = this._getForeignKeyByField();
			if (whereField) {
				result.push(`${whereField} == '${this.dataValue}'`)
			}

			if (this.where) {
				return `(${this.where}) && (${result.join(' || ')})`
			}

			return result.join(' || ')
		},

		_getForeignKeyByField() {
			let fields = this.field.split(',');
			let whereField = null;
			for (let i = 0; i < fields.length; i++) {
				const items = fields[i].split('as');
				if (items.length < 2) {
					continue;
				}
				if (items[1].trim() === 'value') {
					whereField = items[0].trim();
					break;
				}
			}
			return whereField;
		},

		_updateBindData(node) {
			const {
				dataList,
				hasNodes
			} = this._filterData(this._treeData, this.selected)

			let isleaf = this._stepSearh === false && !hasNodes

			if (node) {
				node.isleaf = isleaf
			}

			this.dataList = dataList
			this.selectedIndex = dataList.length - 1

			if (!isleaf && this.selected.length < dataList.length) {
				this.selected.push({
					value: null,
					text: "请选择"
				})
			}

			return {
				isleaf,
				hasNodes
			}
		},

		_updateSelected() {
			let dl = this.dataList
			let sl = this.selected
			let textField = this.map.text
			let valueField = this.map.value
			for (let i = 0; i < sl.length; i++) {
				let value = sl[i].value
				let dl2 = dl[i]
				for (let j = 0; j < dl2.length; j++) {
					let item2 = dl2[j]
					if (item2[valueField] === value) {
						sl[i].text = item2[textField]
						break
					}
				}
			}
		},

		_filterData(data, paths) {
			let dataList = []
			let hasNodes = true

			dataList.push(data.filter((item) => {
				return (item.parent_value === null || item.parent_value === undefined || item.parent_value === '')
			}))
			for (let i = 0; i < paths.length; i++) {
				let value = paths[i].value
				let nodes = data.filter((item) => {
					return item.parent_value === value
				})

				if (nodes.length) {
					dataList.push(nodes)
				} else {
					hasNodes = false
				}
			}

			return {
				dataList,
				hasNodes
			}
		},

		_extractTree(nodes, result, parent_value) {
			let list = result || []
			let valueField = this.map.value
			for (let i = 0; i < nodes.length; i++) {
				let node = nodes[i]

				let child = {}
				for (let key in node) {
					if (key !== 'children') {
						child[key] = node[key]
					}
				}
				if (parent_value !== null && parent_value !== undefined && parent_value !== '') {
					child.parent_value = parent_value
				}
				result.push(child)

				let children = node.children
				if (children) {
					this._extractTree(children, result, node[valueField])
				}
			}
		},

		_extractTreePath(nodes, result) {
			let list = result || []
			for (let i = 0; i < nodes.length; i++) {
				let node = nodes[i]

				let child = {}
				for (let key in node) {
					if (key !== 'children') {
						child[key] = node[key]
					}
				}
				result.push(child)

				let children = node.children
				if (children) {
					this._extractTreePath(children, result)
				}
			}
		},

		_findNodePath(key, nodes, path = []) {
			let textField = this.map.text
			let valueField = this.map.value
			for (let i = 0; i < nodes.length; i++) {
				let node = nodes[i]
				let children = node.children
				let text = node[textField]
				let value = node[valueField]

				path.push({
					value,
					text
				})

				if (value === key) {
					return path
				}

				if (children) {
					const p = this._findNodePath(key, children, path)
					if (p.length) {
						return p
					}
				}

				path.pop()
			}
			return []
		}
	}
}
